A method for detecting boron isotope ratio and total boron concentration in solution based on microwave plasma emission spectrum

Abstract

This invention provides a method for detecting the boron isotope ratio and total boron concentration in solution based on microwave plasma emission spectroscopy. The method includes: directly exciting a boron-containing solution sample to be tested using a microwave plasma excitation source; obtaining the boron atom emission spectrum and BO2 molecule emission spectrum of the boron-containing solution sample after subtracting the blank spectrum; configuring a standard solution calibration set; acquiring the spectral data of the standard solution calibration set after subtracting the blank spectrum; establishing a calculation model based on the spectral data; inputting the boron atom emission spectrum or BO2 molecule emission spectrum of the boron-containing solution sample to the calculation model; and outputting the boron isotope ratio or total boron concentration of the boron-containing solution sample. This method for detecting the boron isotope ratio and total boron concentration in solution based on microwave plasma emission spectroscopy can meet the needs of online or real-time analysis.

Description

Technical Field

[0001] This invention relates to the field of spectroscopic analysis and isotope detection technology, and in particular to a method for detecting the proportion of boron isotopes and the total boron concentration in a solution based on microwave plasma emission spectroscopy. Background Technology

[0002] Boron has two stable isotopes. 10 B and 11 B, whose isotopic ratios vary significantly in nature, is an important tracer in geochemistry, oceanography, and environmental science. More importantly, it is crucial in the nuclear industry. 10 B, due to its extremely high thermal neutron absorption cross section, is widely used as a neutron poison. The precise control and real-time monitoring of its isotope ratios and concentrations are directly related to the safe operation of nuclear reactors. Existing detection methods mainly include thermal ionization mass spectrometry (TIMS) and multi-receiver inductively coupled plasma mass spectrometry (MC-ICP-MS), but these methods have extremely complex analytical procedures, slow analysis speeds, high operating costs, and stringent instrument operation and maintenance requirements, making it difficult to meet the needs of online or real-time analysis and hindering the refinement of water quality management in nuclear power plants. Summary of the Invention

[0003] This invention provides a method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy, which can meet the needs of online or real-time analysis.

[0004] This invention provides a method for detecting the proportion of boron isotopes and the total boron concentration in a solution based on microwave plasma emission spectroscopy, comprising: The boron-containing solution sample to be tested is directly excited using a microwave plasma excitation source to obtain the boron atom emission spectrum and BO2 molecule emission spectrum of the sample after subtracting the blank spectrum; a standard solution calibration set is configured; the spectral data of the standard solution calibration set after subtracting the blank spectrum is obtained; a calculation model is established based on the spectral data; the boron atom emission spectrum or BO2 molecule emission spectrum of the sample to be tested is input into the calculation model, and the boron isotope ratio or total boron concentration of the sample to be tested is output.

[0005] In one embodiment of the present invention, a standard solution calibration set is configured, specifically including: Using 99% abundance 10 Boric acid and 11 Boric acid was used to prepare stock solutions; the two stock solutions were mixed to obtain standard solutions with different isotope ratios; the total boron concentration was kept consistent, and only the isotope ratios were changed, which were then used as calibration sets.

[0006] In one embodiment of the present invention, the spectral data of the standard solution calibration set after subtracting the blank spectrum is obtained, and a calculation model is established based on the spectral data, specifically including: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; Preprocessing operations are performed on the BO2 molecular spectral data, including smoothing and denoising, differential processing, and spectral normalization. Generate a spectral data matrix X from the preprocessed BO2 molecular spectral data. m×n , where m is the number of spectra and n is the number of wavelength points; With spectral data matrix X m×n As the independent variable, the calibration set is based on a known set of standard solutions. 10 With B abundance as the dependent variable, a regression model was established using the partial least squares regression algorithm. The leave-one-out cross-validation method is used to iterate through different numbers of latent variables, calculate the root mean square error of cross-validation corresponding to each number of latent variables, and determine the number of latent variables corresponding to the minimum number of latent variables to obtain the final regression model. The emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum is used to generate a spectral data matrix X'. The spectral data matrix X' is then input into a regression model to output the boron isotope ratio of the boron-containing solution sample.

[0007] In one embodiment of the present invention, a partial least squares regression algorithm is used to establish a regression model, specifically: Y = XB + E, where X is the spectral data matrix; Y is the known standard solution calibration set. 10 B abundance; B is the regression coefficient; E is the error term.

[0008] In one embodiment of the present invention, the emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum is used to generate a spectral data matrix X'. The spectral data matrix X' is then input into a regression model to output the boron isotope ratio of the boron-containing solution sample. Specifically, this includes: The emission spectra of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum are used to generate a spectral data matrix X'. This spectral data matrix X' is then input into a regression model to output the emission spectra of the boron-containing solution sample. 10 B abundance Y', obtained through the formula: This is converted into the boron isotope ratio of the boron-containing solution sample to be tested.

[0009] In one embodiment of the present invention, the spectral data of the standard solution calibration set after subtracting the blank spectrum is obtained, and a calculation model is established based on the spectral data, specifically including: Obtain the boron atom spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum, and construct a two-dimensional data matrix D; The number of chemical components is set to 2. Non-negative constraints are applied to the spectrum and concentration. The multivariate curve resolution-alternating least squares algorithm is used to decompose and iteratively solve the two-dimensional data matrix D. After the algorithm converges, the pure spectra and abstract concentration distributions of the two components are output, and a matrix is ​​generated. Based on the spectral matrix S and the concentration matrix C, a quantitative calibration model for boron isotope ratios is constructed. The spectral matrix S of the standard solution is fixed as a known parameter. The boron atom emission spectrum of the boron-containing solution sample to be tested, after subtracting the blank spectrum, is used to construct a two-dimensional data matrix D'. Under the condition that the spectral matrix S of the standard solution is fixed as a known parameter, the multivariate curve-resolved alternating least squares algorithm is used to solve the concentration matrix C' of the boron-containing solution sample to be tested. The concentration matrix C' is input into the boron isotope ratio quantitative calibration model, and the boron isotope ratio of the boron-containing solution sample to be tested is output.

[0010] In one embodiment of the present invention, the formula for decomposing and iteratively solving the two-dimensional data matrix D using the multivariate curve resolution-alternating least squares algorithm is: D = CS T +E, where D is a two-dimensional data matrix, C is an abstract concentration distribution matrix in each sample, and S T Let E be the pure spectral matrix of the two components, and E be the error term.

[0011] In one embodiment of the present invention, a boron isotope ratio quantitative calibration model is constructed based on the spectral matrix S and the concentration matrix C, specifically including: The corresponding values ​​in the concentration matrix C 10 B isotopic components and 11 The abstract concentration values ​​of the B isotope components are denoted as C. 10,i With C 11,i Where i represents the i-th standard solution sample, the spectral response ratio parameter is constructed for each standard solution sample:

[0012] Using standard solutions with known isotopic compositions, the true isotopic abundance ratios can be obtained:

[0013] With R i T is the independent variable. i A linear regression was performed on the dependent variable to establish a quantitative calibration model for boron isotope ratios: .

[0014] In one embodiment of the present invention, the spectral data of the standard solution calibration set after subtracting the blank spectrum is obtained, and a calculation model is established based on the spectral data, specifically including: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; A total boron concentration-spectral intensity calibration model was established based on BO2 molecular spectral data. Input the emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum into the spectral concentration-spectral intensity calibration model, and output the total boron concentration of the boron-containing solution sample.

[0015] In one embodiment of the present invention, a total boron concentration-spectral intensity calibration model is established based on BO2 molecular spectral data, specifically including: A total boron concentration-spectral intensity calibration model was established based on BO2 molecular spectral data using a multi-wavelength point calibration model or a multivariate regression model.

[0016] The beneficial effects of this invention are: The present invention discloses a method for detecting the boron isotope ratio and total boron concentration in solution based on microwave plasma emission spectroscopy. First, a boron-containing solution sample is directly excited using a microwave plasma excitation source. The emission spectra of boron atoms and BO2 molecules in the sample, after subtracting the blank spectrum, are obtained. A standard solution calibration set is then configured, and the spectral data of this calibration set after subtracting the blank spectrum are acquired. A computational model is established based on the spectral data. Finally, the boron atom emission spectrum or BO2 molecule emission spectrum of the boron-containing solution sample is input into the computational model, which outputs the boron isotope ratio or total boron concentration of the sample. Compared to existing detection methods, this invention directly excites liquid samples using microwave plasma emission spectroscopy, directly analyzes solution samples, and combines a computational model to detect the proportion of boron isotopes and the total boron concentration in the solution. Unlike thermal ionization mass spectrometry, it eliminates the need for cumbersome sample chemical separation, purification, and drying pretreatment steps, and avoids the dependence of plasma mass spectrometry on high-vacuum systems and complex ion source maintenance. This significantly simplifies the operation process, shortens the detection cycle, and reduces operating costs, meeting the needs of online or real-time analysis and improving the precision of water quality management in nuclear power plants. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram: Figure 1 This is a schematic diagram of the process structure of a method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy, according to an embodiment of the present invention. Figure 2A schematic diagram of the pure spectral structure of boron atoms in Example 2 provided in one embodiment of the present invention; Figure 3 A schematic diagram of the fitting curve structure of the boron isotope ratio and the actual ratio obtained in Example 2 of this invention; Figure 4 To illustrate an embodiment of the present invention, we provide a molecular spectrum of different concentrations, calibration curve parameters, and detection limit diagram in Example 3, wherein (a) represents the molecular spectrum of different concentrations; (b) represents the wavelength distribution of the slope of the calibration curve; (c) represents the wavelength distribution of the intercept of the calibration curve; (d) represents the wavelength distribution of the R2 of the calibration curve; and (e) represents the wavelength distribution of the detection limit. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0022] Please see Figures 1 to 4 This invention provides a method for detecting the proportion of boron isotopes and the total boron concentration in a solution based on microwave plasma emission spectroscopy, comprising: Step S1: Directly excite the boron-containing solution sample to be tested using a microwave plasma excitation source, and obtain the boron atom emission spectrum and BO2 molecule emission spectrum of the boron-containing solution sample to be tested after subtracting the blank spectrum; In this step, the microwave plasma torsion (MPT) source is an atomic emission spectrometry technique. Its principle is to use microwave energy to generate plasma as an excitation source, exciting elements in the sample and causing them to emit characteristic spectra, thereby enabling qualitative and quantitative elemental analysis. The boron-containing solution sample to be tested can be excited using an MPT spectrometry system. The MPT spectrometry system can employ conventional techniques in this field and may include: a solution introduction unit (including a peristaltic pump, concentric nebulizer, cyclone chamber, etc.), a microwave plasma excitation unit, a spectral acquisition unit (including optical fibers, spectrometers, etc.), and control and data processing software. Before exciting the boron-containing solution sample, the operating parameters of the MPT spectrometry system can be optimized to obtain a stable BO2 molecule emission spectrum with the best signal-to-noise ratio. The specific optimization parameter ranges are shown in Table 1 below. Table 1 Optimization parameters for the MPT spectral analysis system

[0023] After optimization, the boron-containing solution sample to be tested is stably delivered to the concentric nebulizer via a peristaltic pump. Under the action of the carrier gas, a uniform aerosol is formed. After further screening in the nebulization chamber, the aerosol is loaded into the excitation region of the MPT, which efficiently excites the boron-containing aerosol, thereby generating boron atom emission spectra and BO2 molecule emission spectra.

[0024] To ensure accurate acquisition of boron atom emission spectra and BO2 molecule emission spectra, this step focuses on the following: for the BO2 molecule spectral path, BO2 molecule spectral data are acquired in the wavelength range of 400 nm to 600 nm; for the boron atom spectral path, characteristic boron atom spectral lines (BI208.888 nm, BI208.957 nm, BI249.677 nm, BI249.772 nm, etc.) are acquired, preferably a narrow band spectrum centered on BI208.957 nm (such as 208.930 nm to 208.980 nm), with a resolution better than 10 pm. Furthermore, a rigorous cleaning procedure must be performed before analyzing each boron-containing solution sample or after analyzing high-concentration samples to suppress the memory effect: A 1% mannitol aqueous solution (as a boron complexing agent) is passed through to clean the sample introduction area of ​​the MPT spectroscopic analysis system (including the nebulizer, nebulization chamber, and torch inner wall) for 3 minutes, followed by a pure water rinse for 1-2 minutes. Then, a blank solution matching the matrix of the boron-containing solution sample is passed through, and the blank spectrum of this blank solution is collected and saved. Next, the boron-containing solution sample is passed through, and the boron atom emission spectrum and BO2 molecule emission spectrum of the sample are collected. The blank spectrum is then subtracted from the boron atom emission spectrum and BO2 molecule emission spectrum. This results in a more complete boron atom emission spectrum and BO2 molecule emission spectrum, improving the accuracy of subsequent boron isotope ratio and total boron concentration detection.

[0025] Step S2: Configure the standard solution calibration set; In one embodiment of the present invention, step S2 may specifically include: Step S21: Use 99% abundance 10 Boric acid and 11 Prepare stock solutions of boric acid separately; mix the two stock solutions to obtain (e.g., 10-15) standard solutions with different isotope ratios; keep the total boron concentration consistent (e.g., 1000 μg / mL), only change the isotope ratios, and use these as the calibration set.

[0026] Step S3: Obtain the spectral data of the standard solution calibration set after subtracting the blank spectrum, establish a calculation model based on the spectral data, input the boron atom emission spectrum or BO2 molecule emission spectrum of the boron-containing solution sample to be tested into the calculation model, and output the boron isotope ratio or total boron concentration of the boron-containing solution sample to be tested.

[0027] This step can calculate the boron isotope ratio of the boron-containing solution sample based on the BO2 molecular spectral data; it can also calculate the boron isotope ratio of the boron-containing solution sample based on the boron atom spectral data; and it can also calculate the total boron concentration of the boron-containing solution sample based on the BO2 molecular spectral data; see below: To enable the detection of boron isotope ratios in boron solution samples based on BO2 molecular spectral data, in one embodiment of the present invention, step S3 may specifically include: Step SA31: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; In this step, spectral data is collected multiple times for each standard solution using step S1. For example, 5 to 20 BO2 molecular spectra at 400nm-600nm are collected for each standard solution. Each spectrum is averaged by multiple scans to reduce the influence of random noise.

[0028] Step SA32: Perform preprocessing operations on the BO2 molecular spectral data, including smoothing and denoising, differential processing, and spectral normalization. This step involves preprocessing the BO2 molecular spectral data to enhance spectral features related to isotope ratios and suppress noise and matrix fluctuations. Smoothing and denoising can be performed using the Savitzky-Golay smoothing algorithm; differentiation can be done using first-order differentiation; and spectral normalization can be achieved using the standard normalization (SNV) method. The formula for the normalization method is as follows: ,in, Let be the spectral intensity at the i-th wavelength. This is the average intensity across all wavelengths of the spectrum. The standard deviation of the spectral intensity is... This represents the normalized spectral intensity.

[0029] Step SA33: Generate a spectral data matrix X from the preprocessed BO2 molecular spectral data. m×n , where m is the number of spectra and n is the number of wavelength points; Step SA34, using the spectral data matrix X m×n As the independent variable, the calibration set is based on a known set of standard solutions. 10 With B abundance as the dependent variable, a regression model was established using the partial least squares regression algorithm. In this step, the standard solution calibration set is known. 10 B / 11 A standard boric acid solution with ratio B was used to generate a spectral data matrix X based on the BO2 molecular spectral data from 400 nm to 600 nm after pretreatment. m×n As the independent variable, with known... 10 Using B abundance as the dependent variable, a regression model was established using the partial least squares regression (PLSR) algorithm.

[0030] In one embodiment of the present invention, step SA34 employs a partial least squares regression algorithm to establish a regression model, specifically: Y = XB + E, where X is the spectral data matrix; Y is the known standard solution calibration set. 10 B abundance; B is the regression coefficient; E is the error term.

[0031] Step SA35: Use the leave-one-out cross-validation method to iterate through different numbers of latent variables, calculate the root mean square error of cross-validation (RMSECV) corresponding to each number of latent variables, and determine the number of latent variables corresponding to the minimum RMSECV as the optimal number of latent variables to obtain the final regression model. In this step, the Leave-One-out Cross-Validation (LOOCV) method is used to iterate through different numbers of latent variables. The specific formula is as follows:

[0032] Where n is the number of samples; yi is the true value of the i-th sample; The model is used to predict the value of the i-th sample after removing the i-th sample, thus obtaining the optimal regression model.

[0033] Step SA36: Generate a spectral data matrix X' from the emission spectrum of BO2 molecules after subtracting the blank spectrum from the boron-containing solution sample to be tested. Input the spectral data matrix X' into the regression model to output the boron isotope ratio of the boron-containing solution sample to be tested.

[0034] In one embodiment of the present invention, step SA36 may specifically include: The emission spectra of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum are used to generate a spectral data matrix X'. This spectral data matrix X' is then input into a regression model to output the emission spectra of the boron-containing solution sample. 10 B abundance Y', obtained through the formula: This is converted into the boron isotope ratio of the boron-containing solution sample to be tested.

[0035] In response, the present invention provides the following embodiments: Example 1: Calculation of boron isotope ratio in a boron-containing solution sample based on BO2 molecular spectral data from spectral data; Experimental preparation: High abundance 10 B boric acid solid ( 10 B abundance 99.2%); high abundance 11 B boric acid solid ( 11 B abundance 99.9%); ultrapure water (18.2 MΩ·cm); 1% (w / v) mannitol aqueous solution; Preparation of standard solutions: using high abundance... 10 B and 11 Prepare a single-standard stock solution of boric acid solid (B) with a concentration of 2500 μg / mL (based on total boron). Mix the two stock solutions according to the proportions shown in Table 2 below, and dilute with ultrapure water to prepare a solution with a fixed total boron concentration of 1000 μg / mL. 10 Eleven calibration solutions with B abundance gradients from 0.001 to 0.992.

[0036] Table 2. Molecular spectroscopy calibration set samples and their corresponding isotopic proportions.

[0037] Instruments and parameters: A fiber optic spectrometer with a wavelength range of 300nm-700nm and a minimum wavelength spacing of 0.13nm was used. The optimized parameters of the MPT spectral analysis system are shown in Table 1.

[0038] Experimental steps: a) Before each sample injection, clean the injection system with 1% mannitol solution for 3 minutes, then rinse with ultrapure water for 2 minutes; b) Introduce a blank solution matching the sample matrix, collect and save the blank spectrum as the blank spectrum for this batch of analysis; c) Introduce 11 standard solutions sequentially into the MPT spectral analysis system, collect the spectrum for each standard solution, and after the signal stabilizes (e.g., after 30 seconds), continuously collect 5 BO2 molecular spectra for modeling to ensure stability; d) Preprocess the BO2 molecular spectral data, performing smoothing and noise reduction, differential processing, and spectral normalization in sequence, with a processing range of 400nm-600nm; e) Use the spectral data matrix X generated from the preprocessed spectral data of the 11 samples as the independent variable, corresponding to the known standard solutions. 10Using B abundance as the dependent variable, a partial least squares regression model was established, and cross-validation was used to determine the optimal number of latent variables as 6, resulting in the final regression model; f) The cross-validation results show that the regression model predicts the abundance of samples in the calibration set. 10 The correlation coefficient between B abundance and the true value is R² > 0.9999, and the root mean square error of cross-validation (RMSECV) is 0.0014 (abundance units); g) Unknown sample test: Prepare a boric acid solution with a total boron concentration of 1000 μg / mL at natural abundance (theoretical). 10 B abundance is approximately 0.198) as the test set. Its spectrum is obtained following the same procedure (AD step), and input into the regression model. The test set consists of 5 spectra. 10 The predicted abundance of B is 0.1997. The prediction results are then converted to... 10 B: 11 The B ratio resulted in a relative standard deviation (RSD) of 0.95% for the prediction results (i.e., precision of approximately 9.5‰, 2σ), and a relative deviation of approximately 1.1% for the predicted mean.

[0039] In summary, this embodiment demonstrates that by using MPT to excite the BO2 molecular spectrum, combined with a specific pretreatment process and PLSR to establish a regression model, a rapid and high-precision quantitative analysis of the boron isotope ratio in solution can be achieved using a low-resolution spectrometer, with precision reaching the advanced level of optical methods.

[0040] To enable the detection of boron isotope ratios in a boron solution sample based on boron atomic spectral data, in one embodiment of the present invention, step S3 may specifically include: Step SB31: Obtain the boron atom spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum, and construct a two-dimensional data matrix D; In this step, boron atomic spectral data (narrow band spectrum centered at BI208.957nm) can be acquired for each standard solution using step S1, and a two-dimensional data matrix D (m×n, where m is the number of samples and n is the number of wavelength points) can be constructed.

[0041] Step SB32: Set the number of chemical components to 2, apply non-negative constraints on spectra and concentrations, and use the multivariate curve resolution-alternating least squares algorithm to decompose and iteratively solve the two-dimensional data matrix D. After the algorithm converges, output the pure spectra and abstract concentration distributions of the two components, and generate a matrix. In this step, the chemical group score is set to 2 to correspond to 10 B and 11B. Apply non-negative constraints on the spectrum and concentration, and use the multivariate curve-resolved alternating least squares algorithm (MCR-ALS) to decompose and iteratively solve the two-dimensional data matrix D. After the algorithm converges, it outputs the estimated pure spectra of the two components and the abstract concentration distribution in each sample. Then, the spectral matrix S and the concentration matrix C are established respectively.

[0042] In one embodiment of the present invention, the formula for decomposing and iteratively solving the two-dimensional data matrix D using the multivariate curve resolution-alternating least squares algorithm can be: D = CS T +E, where D is a two-dimensional data matrix, C is an abstract concentration distribution matrix in each sample, and S T Let E be the pure spectral matrix of the two components, and E be the error term.

[0043] Step SB33: Based on the spectral matrix S and the concentration matrix C, construct a quantitative calibration model for boron isotope ratios; In one embodiment of the present invention, step SB33 specifically includes: Step SB331: The corresponding values ​​in the concentration matrix C are... 10 B isotopic components and 11 The abstract concentration values ​​of the B isotope components are denoted as C. 10,i With C 11,i Where i represents the i-th standard solution sample, the spectral response ratio parameter is constructed for each standard solution sample:

[0044] Step SB332: Using a standard solution with known isotopic composition, obtain the true isotopic abundance ratio:

[0045] Step SB333, with R i T is the independent variable. i A linear regression was performed on the dependent variable to establish a quantitative calibration model for boron isotope ratios: .

[0046] Step SB34: Fix the spectral matrix S of the standard solution to known parameters, construct a two-dimensional data matrix D' from the boron atom emission spectrum of the boron-containing solution sample after subtracting the blank spectrum, and use the multivariate curve resolution-alternating least squares algorithm to solve the concentration matrix C' of the boron-containing solution sample to be tested. Input the concentration matrix C' into the boron isotope ratio quantitative calibration model and output the boron isotope ratio of the boron-containing solution sample to be tested.

[0047] In this step, with the spectral matrix S of the standard solution fixed at known parameters, the concentration matrix C' of the boron-containing solution sample to be tested is solved using a multivariate curve-resolved alternating least squares algorithm. The concentration matrix C' includes the concentration vector C of the boron-containing solution sample to be tested. 10,unk With C 11,unk Further calculation of C 10,unk With C 11,unk The ratio:

[0048] And substitute it into the above boron isotope ratio quantitative calibration model:

[0049] This outputs the boron isotope ratio of the boron-containing solution sample to be tested.

[0050] In response, the present invention provides the following embodiments: Example 2: Calculation of boron isotope ratio in a boron-containing solution sample based on boron atom spectral data; The experimental preparation was basically the same as in Example 1, except that high abundance was used. 10 B and 11 Boric acid (B-type) was prepared to achieve a total boron concentration of 100 μg / mL. 11 B: 10 Five mixed standard solutions with B varying from 0.01 to 3.85 (see Table 3 below).

[0051] Table 3 Standard Samples for Boron Atom Spectroscopy Test Set

[0052] Instruments and parameters: The optimized parameters of the MPT spectral analysis system are shown in Table 1 above. A echelle spectrometer is used, with a resolution of approximately 5 pm (0.005 nm).

[0053] Experimental steps: Basically the same as in Example 1, except for: a) After cleaning the system, analyze five standard solutions sequentially, collecting spectral data for each standard solution centered on the BI 208.957nm characteristic spectral line with the largest isotopic shift; b) Subtract blanks from the spectra and extract spectral vectors of nine consecutive wavelength points (approximately 5 pm apart) centered at 208.957nm; c) Assemble the spectral data from the five samples into an original data matrix (5×9), setting the chemical component score to 2 (representing...). 10 B and 11 (Contribution of B), applying non-negativity constraints on spectral and concentration, and using a multivariate curve-resolved alternating least squares algorithm to decompose and iteratively solve the two-dimensional data matrix D. After the algorithm converges; d) the outputs correspond to 10 B and 11The two pure spectral profiles of the spectral line shape of B (e.g.) Figure 2 (As shown) and the abstract concentrations of the two components in each sample, the wavelength spacing between the peaks of the two pure component atomic spectra obtained by interpolating the spectra of the two pure components is approximately 2.5 pm, which is basically consistent with the theoretical isotopic shift. e) Establish a calibration model: For each sample, calculate the abstract concentration ratio given by MCR-ALS ( 11 B: 10 B) is used as the predicted value. A linear regression is performed between this predicted value and the theoretical isotope ratio of the sample to obtain the calibration curve (e.g., ...). Figure 3 As shown, R² > 0.99.

[0054] Conclusion: This result shows that even for atomic spectral lines with extremely small shifts, isotopic information can be effectively extracted through high-resolution acquisition combined with advanced chemometric analysis, verifying the feasibility of the MPT-excited atomic spectral path.

[0055] To enable the detection of total boron concentration in a boron solution sample based on BO2 molecular spectral data, in one embodiment of the present invention, step S3 may specifically include: Step SC31: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; In this step, spectral data is collected multiple times for each standard solution using step S1. For example, 5 to 20 BO2 molecular spectra at 400nm-600nm are collected for each standard solution. Each spectrum is averaged by multiple scans to reduce the influence of random noise.

[0056] Step SC32: Establish a total boron concentration-spectral intensity calibration model based on BO2 molecular spectral data; In this step, a multi-wavelength calibration model can be used to establish a total boron concentration-spectral intensity calibration model based on BO2 molecular spectral data. A wavelength range of 450nm-590nm is selected, and the net spectral intensity at each wavelength point is linearly fitted to the total boron concentration to obtain the spectral intensity-concentration standard curve for each wavelength point. The calibration equation for each wavelength point is as follows: C i Total boron concentration; k i b i The slope and intercept of the calibration curve at the i-th wavelength point; I i The net spectral intensity at the i-th wavelength point can be used; alternatively, a multivariate regression model can be employed to perform multivariate regression on the spectral intensity of the BO2 molecule, establishing a total boron concentration-spectral intensity calibration model.

[0057] Step SC33: Input the emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum into the spectral concentration-spectral intensity calibration model, and output the total boron concentration of the boron-containing solution sample.

[0058] In this step, when a multi-wavelength calibration model is used to establish a total boron concentration-spectral intensity calibration model based on BO2 molecular spectral data, the total boron concentration Ci can first be predicted by the net spectral intensity of each wavelength point of the boron-containing solution sample to be tested and the corresponding calibration equation. Then, the total boron concentration of the unknown sample is:

[0059] Where w i Let w be the weight of the i-th wavelength point, and n be the number of effective wavelength points involved in the calculation; when the weight w i When the signal is a pulse sequence, the multi-wavelength fusion result degenerates into a single-wavelength concentration prediction; when the weight w i =k i hour,

[0060] Example 3: Calculation of total boron concentration in the boron-containing solution sample based on BO2 molecular spectral data from the spectral data; The experimental preparation was basically the same as in Example 1, except that a series of standard solutions with total boron concentrations of 5 μg / mL, 50 μg / mL, 500 μg / mL, 1200 μg / mL, 2000 μg / mL, and 3000 μg / mL were prepared.

[0061] The instrument and parameters are basically the same as in Example 1, except that the spectral acquisition range is focused on the strong emission band of BO2 in the range of 450-590nm.

[0062] Experimental Procedure: The procedure is basically the same as in Example 1, except that: a) Standard solutions are introduced into the MPT spectral analysis system sequentially from low to high concentrations, and spectra are acquired (20 spectra are averaged for each concentration point). b) Within the spectral range of 450 nm to 590 nm, one or more characteristic wavelength points (e.g., a peak at 516.0 nm) are selected, or the integrated intensity of a specified band within this range is calculated. A linear regression is performed using this spectral intensity value I against the corresponding total boron concentration C to establish a calibration curve (in the form of: The calibration curve and the result of the limit of detection (LOD) are as follows: Figure 4 As shown. Experiments show that the linear relationship is excellent within this range (R2>0.9992). The detection limit is 1.7 μg / mL, corresponding to a wavelength of 566 nm, obtained by collecting blank spectra 20 times according to the 3σ criterion. d) Determination of unknown samples: A boric acid solution of unknown concentration (actual concentration approximately 1000 μg / mL) was prepared. The spectral intensity at 566 nm after subtracting the blank was measured. Substituting into the calibration curve above, the concentration was calculated to be 987 μg / mL, and the recovery rate was 98.7%.

[0063] Conclusion: This example demonstrates that the spectral intensity of BO2 molecules excited by MPT exhibits an excellent linear relationship with the total boron concentration in the concentration range of 5 μg / mL to 3000 μg / mL. The method has a low detection limit and can meet the needs of rapid and accurate determination of boron concentration over a wide range in actual samples.

[0064] In summary, the method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy of the present invention has the following beneficial effects: Employing a microwave plasma torch (MPT) as the excitation source, this method offers the dual advantages of continuous and stable output and moderate plasma temperature. It eliminates the need for time window control and time synchronization triggering, resulting in high spectral repeatability. Furthermore, the relatively low plasma temperature is particularly conducive to the formation of boron oxide molecules, providing favorable conditions for molecular spectroscopic determination of boron isotopes. It can directly analyze liquid samples without cumbersome pretreatment steps such as drying and curing, making it particularly suitable for continuous online monitoring in industrial settings. With low purchase and maintenance costs, it boasts excellent economic viability and promotional value. The short analysis cycle (down to minutes) facilitates automated control, making it suitable for continuous, real-time online monitoring in applications such as nuclear power plant cooling water. It reaches the advanced level of current optical methods for boron isotope determination, meeting the accuracy requirements of practical applications such as nuclear power plant cooling water management. Its environmental requirements are lower than those of large mass spectrometers, exhibiting strong robustness and anti-interference capabilities. It enables rapid determination of the proportion of boron isotopes and total boron concentration in solutions, improving detection efficiency.

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy, characterized in that, include: The boron-containing solution sample to be tested was directly excited using a microwave plasma excitation source, and the emission spectra of boron atoms and BO2 molecules of the boron-containing solution sample after subtracting the blank spectrum were obtained. Configure a standard solution calibration set; Obtain the spectral data of the standard solution calibration set after subtracting the blank spectrum, establish a calculation model based on the spectral data, input the boron atom emission spectrum or BO2 molecule emission spectrum of the boron-containing solution sample to be tested into the calculation model, and output the boron isotope ratio or total boron concentration of the boron-containing solution sample to be tested.

2. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 1, characterized in that, Configure a standard solution calibration set, specifically including: Using 99% abundance 10 Boric acid and 11 Boric acid was used to prepare stock solutions; the two stock solutions were mixed to obtain standard solutions with different isotope ratios; the total boron concentration was kept consistent, and only the isotope ratios were changed, which were used as the calibration set.

3. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 1, characterized in that, Obtain the spectral data of the standard solution calibration set after subtracting the blank spectrum, and establish a calculation model based on the spectral data, specifically including: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; Preprocessing operations are performed on the BO2 molecular spectral data, including smoothing and denoising, differential processing, and spectral normalization. Generate a spectral data matrix X from the preprocessed BO2 molecular spectral data. m×n , where m is the number of spectra and n is the number of wavelength points; With spectral data matrix X m×n As the independent variable, the calibration set is based on a known set of standard solutions. 10 With B abundance as the dependent variable, a regression model was established using the partial least squares regression algorithm. The leave-one-out cross-validation method is used to iterate through different numbers of latent variables, calculate the root mean square error of cross-validation corresponding to each number of latent variables, and determine the number of latent variables corresponding to the minimum number of latent variables to obtain the final regression model. The emission spectrum of BO2 molecules from the boron-containing solution sample to be tested, after subtracting the blank spectrum, is used to generate a spectral data matrix X'. The spectral data matrix X' is then input into a regression model to output the boron isotope ratio of the boron-containing solution sample to be tested.

4. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 3, characterized in that, A partial least squares regression algorithm is used to establish the regression model, specifically: Y = XB + E, where X is the spectral data matrix; Y is the known standard solution calibration set. 10 B abundance; B is the regression coefficient; E is the error term.

5. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 3, characterized in that, The emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum is used to generate a spectral data matrix X'. This spectral data matrix X' is then input into a regression model to output the boron isotope ratios of the boron-containing solution sample, specifically including: The emission spectra of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum are used to generate a spectral data matrix X'. This spectral data matrix X' is then input into a regression model to output the emission spectra of the boron-containing solution sample. 10 B abundance Y', obtained through the formula: This is converted into the boron isotope ratio of the boron-containing solution sample to be tested.

6. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 1, characterized in that, Obtain the spectral data of the standard solution calibration set after subtracting the blank spectrum, and establish a calculation model based on the spectral data, specifically including: Obtain the boron atom spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum, and construct a two-dimensional data matrix D; The number of chemical components is set to 2. Non-negative constraints are applied to the spectrum and concentration. The multivariate curve resolution-alternating least squares algorithm is used to decompose and iteratively solve the two-dimensional data matrix D. After the algorithm converges, the pure spectra and abstract concentration distributions of the two components are output, and a matrix is ​​generated. Based on the spectral matrix S and the concentration matrix C, a quantitative calibration model for boron isotope ratios is constructed. The spectral matrix S of the standard solution is fixed as a known parameter. The boron atom emission spectrum of the boron-containing solution sample to be tested, after subtracting the blank spectrum, is used to construct a two-dimensional data matrix D'. Under the condition that the spectral matrix S of the standard solution is fixed as a known parameter, the concentration matrix C' of the boron-containing solution sample to be tested is solved by the multivariate curve-resolved alternating least squares algorithm. The concentration matrix C' is input into the boron isotope ratio quantitative calibration model, and the boron isotope ratio of the boron-containing solution sample to be tested is output.

7. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 6, characterized in that, The formula for decomposing and iteratively solving a two-dimensional data matrix D using the multivariate curve resolution-alternating least squares algorithm is: D = CS T +E, where D is a two-dimensional data matrix, C is an abstract concentration distribution matrix in each sample, and S T Let E be the pure spectral matrix of the two components, and E be the error term.

8. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 6, characterized in that, Based on the spectral matrix S and the concentration matrix C, a quantitative calibration model for boron isotope ratios is constructed, specifically including: The corresponding values ​​in the concentration matrix C 10 B isotopic components and 11 The abstract concentration values ​​of the B isotope components are denoted as C. 10,i With C 11,i Where i represents the i-th standard solution sample, the spectral response ratio parameter is constructed for each standard solution sample: Using standard solutions with known isotopic compositions, the true isotopic abundance ratios can be obtained: With R i T is the independent variable. i A linear regression was performed on the dependent variable to establish a quantitative calibration model for boron isotope ratios: 。 9. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 1, characterized in that, Obtain the spectral data of the standard solution calibration set after subtracting the blank spectrum, and establish a calculation model based on the spectral data, specifically including: Obtain the BO2 molecule spectral data from the spectral data of the standard solution calibration set after subtracting the blank spectrum; A total boron concentration-spectral intensity calibration model was established based on BO2 molecular spectral data. The emission spectrum of BO2 molecules from the boron-containing solution sample after subtracting the blank spectrum is input into the spectral concentration-spectral intensity calibration model, which outputs the total boron concentration of the boron-containing solution sample.

10. The method for detecting the proportion of boron isotopes and the total boron concentration in solution based on microwave plasma emission spectroscopy according to claim 9, characterized in that, A total boron concentration-spectral intensity calibration model was established based on BO2 molecular spectral data, specifically including: A total boron concentration-spectral intensity calibration model was established based on BO2 molecular spectral data using a multi-wavelength point calibration model or a multivariate regression model.

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